This invention relates generally to bearings and more particularly to cylindrical bearing pockets.
Cylindrical bearings typically require proper diametrical clearance between the outer race of the bearing and the cylindrical bearing pocket in which the bearing rests. To ensure proper pre-loading of the bearing, the clearance must be large enough to allow the bearing to slide axially in the bearing pocket. However, the clearance between the outer race of the bearing and the bearing pocket must also be small enough to restrict side to side movement and rotation of the bearing, which may cause unwanted noise or premature failure of the bearing due to xe2x80x9cpound-out.xe2x80x9d
Cylindrical bearing pockets are typically stamped from thin sheets of steel into a stamped steel xe2x80x9ccap and canxe2x80x9d construction. The stamped steel xe2x80x9ccap and canxe2x80x9d construction is capable of maintaining the proper cylindrical shape throughout most of the bearing pocket. However, the diameter at the bottom of the pocket is often too small thereby inhibiting axial motion of the bearing within the bearing pocket. Because the bearing cannot seat firmly against the bottom of the pocket, the bearing may become pinched and thus may not slide freely within the pocket. Therefore, some bearing pockets are enlarged with a secondary finishing process, such as machining. Machining, however, adds additional cost to the manufacture of the bearing pocket and may also raise quality issues. Roller-burnishing processes have also been used to enlarge the diameter at the bottom of the bearing pocket but are disadvantageous because other areas of the bearing pocket will also be enlarged, possibly becoming oversized. In addition, roller burnishing adds considerable cost to the manufacture of the bearing pocket. Separate spacers or shims have also been employed to address the clearance between the bearing pocket and the outer race of the bearing. Including extra spacers or shims is problematic because of the increased number of parts, manufacturing complexity and cost. Further, extra spacers or shims increase the possibility of improper assembly. For example, the spacer or shim may not be included in the bearing pocket assembly.
In one aspect, a bearing seat is provided that comprises a cylindrical seat defining a cylindrical pocket for at least partially containing a bearing. The cylindrical seat includes a cylindrical first wall and an end wall extending from the cylindrical first wall. The cylindrical first wall has an inner face and the end wall includes an integral shim extending outwardly therefrom. The integral shim is configured to contact a side of an outer race of a bearing such that the side of the outer race of the bearing seats firmly against the integral shim.
In another aspect, a cap and bearing assembly is provided which comprises a bearing that includes an outer race. The outer race includes a side. The assembly further comprises a cap that includes a cylindrical seat that defines a cylindrical pocket for at least partially containing a bearing. The cylindrical seat includes a cylindrical first wall and an end wall that extends from the cylindrical first wall. The cylindrical first wall includes an inner face and the end wall includes an integral shim that extends outwardly from the end wall. The integral shim is configured to contact the side of the outer race of the bearing such that the side of the outer race of the bearing seats firmly against the integral shim.
In yet another aspect, a method is provided for locating a bearing within a cylindrical seat. The bearing includes an outer race having a side and the cylindrical seat includes a cylindrical first wall and an end wall. The method comprises providing an integral shim that extends outwardly from the end wall of the cylindrical seat, and disposing the bearing within the cylindrical seat such that the side of the outer race of the bearing seats firmly against the integral shim.